# Do not perform ident nor DNS lookups (hangs when the port is filtered)
IdentLookups off
UseReverseDNS off

# Port 21 is the standard FTP port.
Port 21

# Umask 022 is a good standard umask to prevent new dirs and files
# from being group and world writable.
Umask 022

# Default to show dot files in directory listings
ListOptions "-a"

# See Configuration.html for these (here are the default values)
#MultilineRFC2228 off
#RootLogin off
#LoginPasswordPrompt on
#MaxLoginAttempts 3
#MaxClientsPerHost none
#AllowForeignAddress off # For FXP

# Allow to resume not only the downloads but the uploads too
AllowRetrieveRestart on
AllowStoreRestart on

# To prevent DoS attacks, set the maximum number of child processes
# to 30. If you need to allow more than 30 concurrent connections
# at once, simply increase this value. Note that this ONLY works
# in standalone mode, in inetd mode you should use an inetd server
# that allows you to limit maximum number of processes per service
# (such as xinetd)
MaxInstances 20

# Set the user and group that the server normally runs at.
User nobody
Group nobody

# Disable sendfile by default since it breaks displaying the download speeds in
# ftptop and ftpwho
UseSendfile no

# This is where we want to put the pid file
ScoreboardFile /var/run/proftpd.score

i continue with that problem.
if i write ftp.xxxx.com i can´t conect but if i write xxxxx.com i can perfect conection.

if i erase this part on proftpd_ispconfig
<VirtualHost 192.168.0.253>
DefaultRoot ~
AllowOverwrite on
Umask 002
</virtualhost>

All ok, but when i create the new one client or Cname or A Record, the file proftp_ispconfig.conf returns to his previous condition. With which it does not work. If I return to erase , it returns to work.

I go to DNS-manager and select my site. I create in an A record "ftp" pointing to the IP public, but i can´t conect.
This message:
Status: Connecting to ftp.airfreenavarra.com ...
Error: Unable to connect!

The dns manager is not nescessarily the authoritive DNS server. Plaese go into the domain control panel of your registry and check if the dns server of the registry or your own server is authoritive for the domain. If the dns server of the registry is authoritive, which I guess, then you will have to create the DNS A-Record there and not in ISPConfig.